This relates generally to integrated circuits and, more particularly, to integrated circuits with memory circuitry.
Integrated circuits often contain memory elements such as random-access memory (RAM) cells. Integrated circuits that include memory cells typically have thousands of data lines (DL). Hundreds of memory cells are attached to each data line. During typical read/write operations, each data line on an integrated circuit has to be precharged to a positive power supply voltage level. Because the length of each data line is long (e.g., hundreds of microns in length) and because each data line is connected to hundreds of memory cells, the capacitance associated with each data line is fairly large.
Conventional precharge circuitry that is used for precharging the data lines includes p-type metal-oxide-semiconductor (PMOS) transistors for pulling the voltage of each data line up towards the positive power supply voltage level. The PMOS precharge transistors are typically turned on and are only turned off during read/write memory operations. The overall memory performance is often limited by the speed at which the precharge circuitry charges up the data lines. In general, data lines with larger capacitances require longer precharge durations.
One way of increasing the speed at which the precharge circuitry pulls up the data lines is to upsize the PMOS precharge transistors (i.e., to increase the device width of the PMOS precharge transistors). Upsizing the PMOS precharge transistors, however, increases static current leakage through the PMOS precharge transistors, which undesirably increases power consumption.